Carbonization apparatus



Get; 24, 1933. c. J. WRIGHT CARBONIZATION APPARATUS Original Filed July 17, 1925 2 Sheets-Sheet 1 INVENTOR arl J Vlrl%fit 8% ATTORNEY.

Oct. 24, 1933.

C; J. WRIGHT CARBONIZATION APPARATUS driginal Filed July 1'1. 1925 lzlllll V I f f I I I,

INVEN 0 Card 1 V ATTORNEY Patented Oct. 24, 1933 PATENT. OFFICE 1,931,972 CARBONIZIATION APPARATUS Carl J. Wright, West New Brighton, Staten Island, N. Y., assignor to Combustion Utilities Corporation, New York, N. Y., a corporation of Maine Original application July 17', 1925,- Serial No.

44,181. Divided and this application July 1,

1931. Serial No. 548,095

Claims.

This invention relates to the heat treatment of solid volatile-containing carbonaceous fuel, and more particularly to an improved apparatus for making combustible gas and industrial coke of 5 high quality from coking bituminous coal. The

present case is a division of my copending application for U. S. patent, Serial #44,l81, filed July 17, 1925 for Carbonization of bituminous fuel, now matured in Patent 1,867,344, issued July 12, 1932.

Most of the coke at present produced for industrial and metallurgical uses is made by distilling bituminous coal out of contact with air in closed retorts or coke ovens of the beehive or by-product type. In these retorts the heating and distillation of the coal is accomplished by the indirect application of heat, i. e. heat for supporting the carbonization is generally suppliedby the combustion of gas in flues around the outside wall of the retort, the heat of the burning gas passing by i convection to the retort wall, then by conduction through the wall, then by radiation and conduction through thecoal charge. The charge of coal in the retort is held in a stationary position during the whole period of its carbonization and accordingly there is little breeze produced and the coke is in large solid pieces having a high market value. Owing-to the resistance to heat transfer of the system and particularly to the low heat conductivity of the coal it is necessary to maintain high temperature gradients between the retort walls and the center of the charge. In fact the walls are'heated to a temperature such that most 'of the volatile products liberated from the coal on distillation are almost immediately cracked down into gaseoushydrocarbons on coming in contact therewith. Another disadvantage of the coke oven methodof carbonizing coal which results from the low heat conductivity of the coal and from the low rate of heat transfer through the 40 system is that it is only possible to treat charges of relatively narrow cross section, and therefore in order to produce gas and coke in commercial quantities a large capital outlay is necessaryfor installing and operating the large number of narrow retorts, each having a relatively low individual fuel treating capacity, which are required.

. Accordingly while the coke oven or indirect heating method of carbonizing coal is in general characterized by the production of relatively large yields of high quality coke and rich coal gas together with a relatively small amount of high temperature tar, the cost of manufacture of the coke and coal gas is so high as to make their use for mosttypes of industrialheating operations prohibitive.

The primary object of thepresent invention is to provide apparatus of thedirect heating type by means ofwhich good yields ofheating gas and. industrial coke of high-quality can be economically produced from coking bituminous coal.

Another object of the invention is to reduce the number of individual apparatus units normally employed and the loss of heat normally resulting from radiation to the atmosphere when bituminous fuel is carbonized by direct heat transfer with a gas of low heat value to produce mixed gas and. coke.

Another object of the invention is to provide apparatus by means of which low B. t. u. gas can be generated and its sensible heat can be efficiently utilized for carbonizing bituminous coal to produce maximum yields of marketable coke, high quality mixed gas and primary tar oil.

In accordance with these objects one feature of the invention contemplates providing an improved apparatus in which the advantageous features of both the standard direct and indirect heating methods of carbonizing coal are applied and by which thesteps of fuel carbonization by direct application of heat and of generation and superheating of a lean gas carbonizing medium can be conducted simultaneously and substantially independently within the confines of a single shaft generator. Another object of the invention is to provide an improved apparatus for making combustible gas of high calorific value by enriching a heated low B. t. u. gas with the volatile products of carbonization of solid volatile-containing carbonaceous fuels.

A further object of the invention is to provide apparatus by, means of which coking bituminous coal can be carbonized by direct heat transfer with heated low B. t. u. gases to produce high quality coke in excess of that required to generate the lowB. t. u. gas carbonizing medium. With these and other objects and features in view the invention consists essentially in the improved apparatus for making combustible gas and industrial coke hereinafter described and particularly defined in the claims. j The various features of the invention are illustrated in the accompanying drawings, inwhich Fig. l is a view in vertical section of a coking and gas generating apparatus of the shaft type having a plurality of metal carbonizing retorts disposed in its upper portion in accordance with the apparatus arrangement "embodying the preferred form of the invention;

' Fig. 2 is a View in enlarged horizontal section of the apparatus taken on the line 2-2 of Fig. 1;

Fig. 3 is a vertical section of a metal carbonizing retort illustrating one type of mechanism by which it can be emptied;

Fig. A 'is a vertical section of a carbonizing retort, showing the arrangement for discharging coke into the gasification zone of the apparatus;

Fig. 5 is a sectional elevation of a carbonizing retort showing the arrangement whereby -carbon ized fuel can be discharged to the outside of the apparatus; and Y Y Fig. 6 is a sectional elevation of the lower portion of a carbonizing retort fitted up with trap doors whereby carbonized fuel can be discharged both to the outside of the shaftand into the gasification chamber. 1

The apparatus embodying the preferred form of the invention, as illustrated in thedrawings,

consists essentially of a shaft generator 10 of thegeneral type and arrangement illustrated in the U. S Patent 1,426,159 to Henry L.'Doherty into which bituminous coal or other solid volatilecontaining carbonaceous fuel which is to be.car bonized is periodically admitted from a hopper 12 by opening one or more of a number of charging gates 14. The interior walls and roof of the shaft 10 are lined with refractory heat insulating material 15, and for purposes of description the interior of the shaft may be considered as comprising an upper heating chamber 16 openly cornmunicating with a lower and larger gas generating chamber 13 (see Fig. 1). The lining of the shaft adjacent the upper part of chamber 18 is constructed to form two vertically spaced circumferential arches or rackbacks 19 and 20, and combined blast inlets and exhaust gas offtakes 21 and 22 open into the interior of the shaft immediately beneath these arches. A charge supporting and waste discharging mechanism 24 is movably mounted in the lower portion of the shaft directly above and vertically spaced from a gas sealing ash door 26 at the base of the shaft. A number of individual carbonizing retorts 28, preferably built of high heat resistant metal, such as chromiiun-nickel-iron alloy, are mounted in the upper heating chamber 16, preferably at regular intervals around the interior of the shaft lining (see Fig. 1). Each of these carbonizing retorts has an opening 29 at the. top and is equipped with'movable or stationary closures at the bottom which seal off the interior of the retort from direct contact with the gas generating chamber 18. In the drawings these retort closures are shown as stationary, plates 29 or as hinged trapdoors 30 arranged to open downwardly and outwardly of the retort to permit carbonized fuel to empty into the gas generating chamber 18 (see Figs. 3 and 4). Preferably some of the retorts are equipped with vertically mounted trapdoors 31, Fig. 5, in the wall of the shaft arranged to open outwardly for the discharge of coke or other carbonized: fuel from the retort directly to the outside of the shaft. In Fig. 1 of the drawings some of the retorts are shown as equipped with downwardly swinging trap doors 30 while others of the retorts are shown as equipped withstationary bases 29 and outwardly swinging trapdoors 31, but as indicated in Fig. 6, it: may often be found of advantage to equip one or more or all, of the retorts with both types of trapdoors. Both doors can then be opened simultaneously to permit a certain proportion of the carbonized fuel produced to pass directly to the outside of the shell as a by-prod- "uct of the operation while at the same time permitting the remainder of the carbonized fuel to empty into the gas generating chamber 18 for use in generating gas and heat sufiicient to carry on the fuel carbonization. A central unobstructed passage 32 extends vertically through the center of heating chamber 16 from the top of the gas generating chamber to an open space in the roof of the generator immediately overlying the 7 open tops ofretorts 28 Likewise between the side walls of adjacent retorts there are additional passage ways 34, and these with the passage 32 save for conducting producer gas, water gas or portion or base of each carbonizing retort preferably to condensing and scrubbing equipment,

purifiers, exhausters and distributing mains or gas holders (not shown).

The method of making industrial coke and fuel gas comprising the preferred form of the invention is carried on in the apparatus illustrated in the drawings substantially as follows:

' Acombustion supporting gas such as air or a mixture of air and steam is blasted periodically or continuously from an outside source through one or both of the inlets 21 or 22 into the upper portion of a bed of carbonized fuel in the gasification chamber 18 to maintain high temperatures therein, and gas generated in the gasification chamber (producer gas, water gas, etc.), after passing through the upper high temperature blast zone of the fuel bed to take on superheat, is conducted directly upward through passage 32 and passages 34 to the top of the shaft above the open tops of carbonizing retorts 28. From the top of the shaft this preheated lean gas is drawn.

downwardly through beds of uncarbonized or partially carbonized bituminous fuel in each of the retorts. After giving up most of its preheat by direct heat transfer with the fuel and picking up volatile components distilled from the fuel the cooled and enriched gas mixture is withdrawn from the retorts through gas offtakes 38 and valves 40, preferably by the operation of exhausters in the purification circuit (not shown).

According to the preferred method of opera- 7 tion the retorts 28 are operated on successive cycles, i. e. the fuel charges of the retorts are maintained at any given instant in progressively advanced stages of carbonization and the retorts are charged and discharged on successive cycles. To charge the retorts the charging gate 14 at the head of the loading chute 36 leading to the top of the particular retort to be charged is opened, and sufficient fuel is admitted from hopper 12 to substantially fill the retort to the top. Valve 40 in the gas offtake 38 leading from the retort being charged is closed during the process of charging and likewise discharge gates 30 and By absorption ofsensible heat from the hot gas thetempe'rature of the fuel quickly rises above the temperature atwhich its volatile components begin to liberate themselves and as the temperature of the fuel continues to rise, more and more of the volatile components of higher and higher boiling point are set free and carried off by the current of heating gas. As the temperature of the heating gas is lowered by direct heat transfer with the fuel during its passage downwardly through the retort some of the higherboiling volatile constituents liberated from the fuel condense out of the gas on the cooler portions of fuel lower down in the retort. By the present method of operation the baffling effect to gas flow which normally results from the condensation of, such volatile components on the fuel in the more fc ommon uprun methods of direct heat carbonie ,zation is not encountered since the condensed liquefied components, i. e. tar oils, are driven downwardly ahead of the gastoward the base of the retort; where the suction created by the out-.

going gas as it leaves the retort through the narrow uptake passage at the downwardly extending intake end 42 of offtake 38 serves to entrainthe condensed oils collected at the foot of the retort with the outgoinggas and to carry them out of r the retort into the condensing and scrubbing apparatus of the purification train.

When carbonizing retorts 28 of large fuel treating capacity are employed in the'top of the gene by means of which to'control the rate at which heating gasis passed through each retort and to maintain the temperature of thegas leaving the shaft at a uniformly low point. Thus as the degree of carbonization of the fuel. in anyretort reaches an advanced stage. at'which a considerable portion of the'volatile components have been liberated, by partly closing or throttling valve 40 the rate at which heating gas is passed through this particular charge of substantially carbonized fuel can be out down and an increased volume of heating gas can'thus be set free for treating the charges of green fuel, or fuel in an earlier stage of carbonization, in some of the other retorts.

After the carbonization of the fuel in any retort has reachedthe desiredstage, valve 40 inthe offtake 38 of this particular retort is closed and trap doors 3G or 31 or both are immediately thrown open to permit the charge of coke or carbonized fuel to empty from the retort into the gasification'chamber 18 of the generator and to the out-' side of the shell. Immediately after the retort is emptied thetraps 30 and 31 are again closed, a fresh charge of fuelis admitted'to the retort by opening charging gate 14, valve 40' in the gasofitake 38 is opened wide to permit a large volume ofthe heating gasvto' pass downwardly through the charge and the carbonizing operation in this retort begins a new cycle. 7

While the type of mechanism to be employed for opening and closing thetrap. door closures 30 and 31 of the carbonizingretorts 28 is not claimed as an essential part of the invention and cycles, with periodic charging and discharging of is left'to the option of the operator, for purposes of illustration several types and arrangements of mechanisms of this class have been suggested in the drawings. Essentiallythe mechanisms-illustrated in the drawings consists of rods 44 extending vertically or diagonally of the'horizontal axis A of the retort and having one end eithermovably mounted in a bearing connected to thebase of the 'retort (see Fig. 5) or attached by pins to the movable trap door closures 30 and 31, and connected at the other end to bellcranks 46, which are in turn connected to and actuated by the piston rods of hydraulic or pneumatic cylinders 48. Thedriving cylinders 48 are preferably supported on the outside of theshell, as by brackets 50, in order that they may be easily accessible for adjustment and repairs. Cross bars 52 are mounted on the rods 44 for. the purpose of breaking up and disturbing the coke in the retorts simultaneously with the movement of the rods in order that the charge will readily empty from the retort when doors 30' and 31 are thrown open.

In case water gas is produced in the gasification chamber 18 of the generator as the medium for carrying heat to support the carbonization of the fuel in retorts 28, the blast air for intermittently raising the temperatureof the bed of fuel in the gasification chamber to incandescence between periods of gas making is preferably admitted through only one of the nostrils 21 or 22- and at the same time the blast gases produced are exhausted through the opposite nostril. These exhaust blast gases are preferably burned in refractory lined preheaters 54 in order that their "ion potential heat may be regenerated andutilized in preheating the blast air and. in generating and superheating the make steam. Between periods of air blasting the steam may be introduced through one or both of nostrils 21 and 22, and

additional steam is admitted into the shaft through a pipe 56 and distributing coil 58, mounted in the lower portion of the generator immediately below the discharge mechanism 24,

If producer as is generator in the gasification zone of the generator and used as the heat- I ing medium for carbonizing thecoal or other bituminous fuel in retorts 28, the blast mixture of air and steam may be introduced simultaneously from thepreheater 54 through one or both of nostrils 21 and 22andpart or all of the blast gases produced may be. passed to the top of the shaft and downwardly through the fuel in the carbonizing retorts, the rate at which gas is passed through any individual retort being regulated by the degree to which valve 40 in the gas offitake 38 is throttled.

In general the amount of coke or carbonized fuel charged into the generator at intervals from the carbonizing retorts 28 'ispreferably regulated erating the low B.t.u. gas carbonizing medium.

,The water, steam or other heat transferring medium which is admitted through inlet pipe'56 and so that the coke will be completely consumed in the high temperature gasification zone 18 in geni distributing coil 58 at ;thebottom of theshaft fuel in the generator, and the heat thus regenerated from the fuel in the generator is then carried upwardly by the steam to the high temperature gasification zone in the form of latent heat of vaporization and superheat in the steam. By operating the carbonizing retorts; 28 on successive each retort, the amount of coke or other carbon- ,ized fuel that is periodically added to the bed of fuel in the gasification chamber 18 by emptying proportion' of the total volume of. the charge in method of operation it is possible to maintain a substantially uniform output of lean gas from the generator and a substantially uniform output of rich gas of a substantially uniform heating value from the carbonizing retorts.

In carbonizing some classes of coking coals it is desirable and sometimes absolutely necessary to charge a certain percentage of coke or other refractory distributing material with the coal into each retort in order to maintain the charge in a suiiiciently porous condition for the passage of heating gases therethrough, particularly during the period in which the coal is passing through the plastic stage of carbonization.

The present method of carbonizing fuel resembles the more common indirect heating or coke oven method in that the coal is held in a stationary position While it is undergoing carbonizaticn and the coke produced accordingly carries a minimum percentage of breeze and is in large solid pieces, comparing favorably in quality with the best grades of coke-oven or beehive coke. The greatly reduced cost of manufacturing coke and :gas products, the greatly increased fuel treating capacity of the apparatus, the great reduction in number of apparatus units and in installation and operating costs of apparatus employed, and the greater efficiency of heat transfer of the systern are among the many features which clearly distinguish the present method from the more common coke-oven or beehive methods.

One advantage of the present method of car bonizing coal is that it can be applied in conjunction with either a water gas or a producer gas operation to yield an enriched mixed gas having a sufficiently high calorific value to make it suitable for most industrial heating operations and for househeating, and to yield valuable by products in the form of excess coke and primary tar oils from the carbonizing step. The yield of tar oils is large since the fuel is carbonized at moderate temperatures by passing heating gas downwardly through the charge in such a way as to drive any tar that is condensed out of the gas ahead of it toward the base of the retort,

rather than permitting the condensed tar to run.

back into a high temperature gas generating zone Where it would be cracked down into fixed gases and lost. Another advantage of the present invention is that it provides for regulating the rate at which heating gas is passed through a charge of the fuel undergoing carbonization in accordance with the stage to which the carbonization has advanced. Thus by putting a large amount of heating gas through a retort which has just been charged, and by simultaneously putting a small amount of gas through a retort which is almost ready to dump, as by opening wide or throttling control valves 40 in the individual retort offtakes, it is possible to control the carbonization of the fuel in such a way as to give maximum yields of tar and an excellent grade of coke and also to effectively utilize the sensible heat carried by the heating gas in completing the fuel carbonization.

Among the chief features of the invention are the various provisions for securing an eflicient utilization of the heat developed in the gas generating zone of the shaft and for reducing to a minimum the losses of heat which normally occur by radiation to the atmosphere and by removal from the apparatus in the form of sensible heat in the generated gases and in the waste fuel. By utilizing a'shaft apparatus having its walls lined 1,931,972 the gasification zone. Accordingly with this with refractory and heat insulating. material and :by utilizing the lower portion of the shaft as a. gas generator and disposingthe retorts in which to carry out the fuel carbonization in the upper Fportion of the same shaft, it is possible with the "present method and apparatus to carry out the carbonizing step with a minimum radiation loss and to effect carb'oni-zation of a maximum volume of raw :solid carbonizable fuel by means of the heat liberated in the gas generating Zone of the By using Carpathians-astute of highly resistant metal construction it is possible itro increase the fuel carbohilzih'g capacity of the ripper portion of a shaft Having a gas generating (chamber of given gas mfaliing capacity in its lower. portion so as to make the combined fuel carbonizzing capacity of tkfe'retorts exceed the fuel treatring capacity ef 'the generating chamber, and thereby with t-his arrangement a relatively large yield of excess coke for industrial sale can be produced in addition to the supply of coke required as fuel an the gas generating chamber to supply heat for carrying on the barbonizing operation. 'R-efhr'ts of metal construction are preferred belcia' ase in general they are much less bulky than retorts of like capacity constructed of refractory material such as fire-brick, and furthermore the.

metal retorts are much stronger, much less subject to develo. ng cracks and gas leaks under pressure and strain, and they can be much more.

readily installed, replaced or repaired in an ap paratus of "this type. Moreover the greater heat conductiyity of the metal is a decided advantage in an apparatus of this type.

The gas generating chamber is arranged the vertically spaced blast air inlets below but near the top the generator reel bed in order that the high temperature gas making zone of the fuel bed can be kept near the top of the fuel for the double purpose, first, of insuring that the generated gases carry a high degree of preheat at the time they leave the top of the fuel bed and also at the time they enter the bed of fresh r'hrl in the carbonizing shell, and second, in order that a maximum amount of the excess heat raia-ted from the blast zone be transmitted directly or indirectly to the outer walls of the carbonizing retort. A factor which materially aids in maintaining the high temperature zone near the top of the generator fuel bedis that the car bonized fuel charge, as emptied from the retorts onto the top of the bed of fuel in the gas generating chamber, generally carries a relatively high degree of preheat. Heat carried out of the gas making zone of the generator as sensible heat in the lean generated gases is substantially all utilined in effecting carbonization of the-fuel in re torts 28 and enrichment of the generated gases with volatile components liberated from the fuel,

while most of the excess heat left in the retorts in the form of carbonized fuel or coke is again returned to the gas making zone of the generator with the hot coke which is charged from the retort directly onto the bed of fuel in the generator.

It is not intended by the above descriptionto limit the invention to the use of a shaft gas generator of any particular type having any particular number or arrangement of carbonizing retorts mounted in its top. It is believed that the particular type of shaft, generator, the number of carbonizing retorts mounted therein, and the manner of arranging carbonizing retorts in the top of the shaft are best left within the option of the operator.

' While the invention has been described with 15:

transversely enlarged .gas generating chamber, a l

" introducing solid fuel into the carbonizing reclosure in the base of the retort arranged to open particular reference to the carbonization ofcoking bituminous coals to produce high B. t. u. mixed gas, marketable coke and primary tar oils, it is apparent that the invention is not restricted to the treating of coals, but may be readily applied, possibly with a few minor changes, to the distillation of other fuels such as lignite coals and oil shales.

The invention having been thus described, what is claimed as new is:

1. Apparatus for carbonizing solid bituminous fuel, comprising a vertical shaft, a gas generat ing chamber in the lower portion of the said shaft, a carbonizing retort mounted in the upper portion of the shaft, means for introducing solid fuel into the said retort, the retort being in permanent communication at its upper end with the interior of the said shaft,-a valve-controlled gas off-take at the base of the retort, a closureat the base of the retort adapted when opened to direct the gravity dischar ge of carbonized fuel downwardly directly from the retort into thegas generating chamber of the shaft, and a removable closure leading from the base of the retort to points outside of the said shaft for the discharge of carbonized fuel therefrom.

2. Apparatus for carbonizing solid fuel comprising a vertically-disposed shaft,the said shaft being enlarged at and below its mid-portion to define an upper heating chamber and a lower,

carbonizing retort mounted adjacent the top of the shaft, a fuel discharge mechanism mounted in the base of the shaft and adapted to support a body of fuel in the gas generating chamber,

" inlets for blast air and steam and outlets for exhaust blast gases respectively connected with the gas generating chamber, means for introducing a heat-transfer fluid into the lower portion of the gas generating chamber, means for tort, a valve-controlled rich gas offtake leading from the lower interior portion of the retort through the shaft wall, the said offtake having a downwardly-extending intake, and a removable downwardly for facilitating the gravity discharge of fuel into the gas generating chamber.

3. Apparatus for carbonizing solid fuel, .comprising a vertically-disposed shaft, the said shaft being enlarged adjacent the mid-portionthereof to define an upper heating chamber and a transversely enlarged lower gas generating chamber, a fuel carbonizing retort mounted within the upper portion of the shaft and having its upper end in open communication with the interior of the shaft, the said retort having an adjustable closure forming the bottom thereof, a second adjustable closure in the side wall of the retort and adapted to open outwardly tofacilitate the discharge of carbonized fuel to points outside of the shaft, means for adjusting the respective closures to open or closed position, a valve-controlled rich gas offtake leading from the lower interior portion of the retort, and means connected with the gas generating chamber for introducing blast air and steam thereinto and for withdrawing exhau'st blast gases therefrom.

4. Apparatus for carbonizing bituminous fuel, comprising a vertically-disposed. shaft having its lower portion of enlarged transverse cross-section to define a gas generating chamber, means connected with the gas generating chamber and adapted to introduce blast air and steam thereto and to withdraw blast gases therefrom, a fuel carbonizing retort mounted in the upperportion of the shaft above the gaspgenerating chamber,said retort being in open communication with the interior of the shaft and having removable closures respectively in its base and in a side wall thereof, mechanically-operated means adapted to move'each of the said closures into open or closed position, means coacting with thesaid mechanically-Operated means and adapted "to facilitate discharge of the contents of the retort when the closure'in'the base of the retort is removed, and a valve-controlled gas offtake leading from the lower portion of the interior. of the retort. I

5. Apparatus for carbonizing solid fuel, comprising an'upright shaft having a gas generating chamber in its lower portion and. a plurality of fuel carbonizing retorts mounted in its upper portion, each of the said retorts being in perma-" nent communication at its upper end with the interior of the shaft, a separately-controlled rev movable closure at the base of each retort, means for independently charging solid fuel into each retort, a valve-controlled gas offtake leading from the lower portion of the interior of each retort, inlets for blast air and steam and outlets for exhaust blast gases connected with'the gas generating chambenand preheaters connected respectively with the said blast inlets "and with the gasofftakes' 6. Apparatus for carbonizing solid fuel, comprising an upright shaft,'-a gas generating chamber in the lower portionof the shaft, conduits connected with the gas generating chamber adapted to introduce air and steam into the said chamber and to withdraw blast gases therefrom, a plurality of horizontally-spaced carbonizing retorts supported in the upper portion of the shaft adjacent the side walls thereof and spaced from the vertical axis of the shaft, each of the said retorts being in permanent communication at their respective upper ends with the interior of the shaft and being provided with a removable bottom member which slopes outwardly and downwardly with respect to the shaft, means for adjusting the said removable bottom member to open or to closed position, means for independently charging fuel into each retort, and independent valve-controlled rich gas oiftakes leading off from the lower interior portion of each retort.

'7. Apparatus for carbonizing solid fuel, comprising an upright shaft, a gas generating cham-' her in the lower portion of the shaft, conduits connected with the gas generating chamber adapted to introduce air and steam into the said chamber and to withdraw blast gases therefrom, a plurality of horizontally-spaced carbonizing retorts supported in the upper portion of the shaft adjacent the side wall thereof and spaced from the vertical axis of the shaft, each of the said retorts being in permanent communication with the interior of the shaft and being closed by a removable bottom closure which is outwardly and downwardly inclined with respect to the shaft,

each of the said retorts also being provided with a'removable closure in a side wall thereof, adapted when opened to effect controlled communication between the retort and the exterior of the shaft, means for adjusting the position of the re- 'spective bottom closures to facilitate discharge of carbonized fuel from each retort to the gas generating chamber, means operatively-connected with each side wall closure in the respective retorts for controlling the discharge of carbonized fuel from each retort to the exterior of the shaft,

means for charging fuel independently to each of the said retorts, and a valve-controlled gas oiftake leading from the lower portion of the interior of each retort.

8. Apparatus for carbonizing solid fuel, comprising an upright shaft, a fas generating chamber in the lower portion of the shaft, means for introducing blast air and steam and for removing blast gases directly from the gas generating chamber, a plurality of vertically-elongated carbonizing retorts laterally mounted at spaced intervals along the shaft inner wall adjacent the upper portion thereof, each of the said retorts being in permanent communication with the interior of the shaft and being closed at the bottom by a removable closure, a plurality of independent means for selectively removing and replacing the said closure of each of the respective retorts, a fuel charging device arranged to independently charge fuel into each retort, and a valve-controlled rich gas ofitake leading from the lower portion of the interior of each retort.

9. Apparatus for carbonizing solid fuel, which comprises an upright shaft, a plurality of elongated carbonizing retorts of smaller total transverse cross section than the cross section of the shaft, the said retorts being supported within the upper portion of the said shaft and being in permanent communication at their respective upper portions with the interior of the latter, each of the'retorts having a removable closure which is downwardly inclined toward the adjacent Wall of the shaft and having means for adjusting the closure in open or closed position, means connected with the lower portion of the shaft for introducing air and steam thereto and for withdrawing blast gases therefrom, means for independently introducing solid fuel into each of the said retorts, a valved-controlled gas offtake leading from the lower portion of each retort to the exterior of the shaft, means in the lower portion of the shaft for introducing a heat exchange fluid thereinto, and means for discharging carbonized fuel from the shaft.

10. Apparatus for carbonizing solid fuel, comprising an upright shaft, a gas generating chamber in thelower portion of the shaft, means for introducing blast air and steam and for removing blast gases directly from the gas generating chamber, a plurality of vertically-elongated carbonizing retorts constructed of heat resistant metal laterally mounted at spaced intervals along the shaft inner wall adjacent the upper portion thereof, each of the said retorts being in permanent communication with the interior of the shaft and being closed at the bottom by a removable closure, a plurality of independent means for selectively removing and replacing the said closure of each of the respective retorts; a fuel charging device arranged to' independently charge 'fuel into each retort, and a valve-controlled rich gas offtake leading from the lower portion of the interior of each retort.

CARL J. WRIGHT. 

